Clutch apparatus for automatic transmission

ABSTRACT

A clutch apparatus including a clutch base having a supporting boss which has first spline grooves, a clutch cover, an output shaft having a sun gear, rotating bearings fitted around the output shaft such that the output shaft can be rotated in one direction and not in the other, planetary gear sections each possessing a guide shaft and a planetary gear which is meshed with the sun gear, a rotating member having a ring gear which is meshed with planetary gears and third spline grooves, a multiple disc clutch member having inner plates which are splined into the rotating member and outer plates which are splined into the supporting boss, a pressing plate letting the inner and outer plates to be tightly engages with one another, pressing means for applying pressing force to the pressing plate, and pressing force adjusting means.

RELATED APPLICATIONS

This application claims the benefit of the Korean application 1999/19340filed May 28, 1999 and the International application PCT/KR00/00517filed May 23, 2000.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a clutch apparatus for an automatictransmission, and more particularly, the present invention relates to aclutch apparatus for an automatic transmission, which is disposedbetween a flywheel of an engine and the automatic transmission in amotor vehicle to connect and disconnect engine power flow to theautomatic transmission and to multiply torque.

2. Background Art

Generally, an engine of a motor vehicle cannot start in a state whereina load is applied thereto and cannot transfer engine power to drivingwheels at the same time when the engine starts. Also, on the contrary tothe fact that the engine rotates only in one direction, the motorvehicle must be able to run in both forward and backward directions. Byreason of these, a clutch is arranged between the engine and atransmission to enable the engine to start in a state wherein no load isapplied thereto. The clutch should be able to gradually transfer enginepower to the driving wheels to allow the motor vehicle to smoothly moveand a speed changing operation to be adequately implemented relying upondriving circumstances. To this end, an automatic transmission which cansimultaneously perform a clutching operation and a shift levermanipulating operation in an automated manner, had been developed.

An automatic transmission generally comprises a combination of a torqueconverter which performs a clutching operation and a transmissionsection (a planetary gear type transmission section) which performs aspeed changing operation. As shown in FIG. 1, the torque converter 10includes a pump 12, a turbine 14 and a stator 16 which are formed withvanes therein. In the torque converter 10, circulating flow in which oilinside a pump impeller is circulated through the pump 12, the turbine 14and the stator 16 by centrifugal force, is produced by an engine. Bythis, the turbine 14 receives engine power to drive a driven shaft 20.In other words, the torque converter 10 simultaneously performs afunction of an automatic clutch and of a torque multiplication. Enginepower which is transferred to the driven shaft 20, automaticallyexecutes a speed changing operation through a hydraulic controlmechanism in the transmission section 30, whereby the torque-multipliedengine power is transferred to the driving wheels.

However, the conventional torque converter suffers from defects in that,since the torque converter transfers engine power to the transmissionsection using fluid, power loss is increased due to fluid friction,etc., whereby a power transferring efficiency is diminished, passing andacceleration capability of the motor vehicle is deteriorated and adifficulty is imposed on obtaining a maximum speed. Moreover, becausethe conventional torque converter must be necessarily equipped with acomplex hydraulic mechanism including the pump, the turbine, the statorand the like and a cooling device for cooling oil which is circulatedthrough the hydraulic mechanism, an entire construction is complicatedand manufacturing cost is elevated.

Furthermore, since force of a driven side of the motor vehicle cannot betransferred to a driving side of the motor vehicle along a reversedirection, an engine brake operation cannot be fulfilled, by which anadverse influence is imposed on safe driving. In addition, due to thefact that it is impossible to start the engine by pushing the motorvehicle, it is difficult to cope with an emergency situation such asdischarge of a battery.

DISCLOSURE OF INVENTION

Accordingly, the present invention has been made in an effort to solvethe problems occurring in the related art, and an object of the presentinvention is to provide a clutch apparatus for an automatictransmission, which is structured using planetary gears, whereby a powertransferring efficiency is increased, a simple construction is achievedand an engine brake operation can be effected.

In order to achieve the above object, according to a first aspect of thepresent invention, there is provided a clutch apparatus for an automatictransmission, which is arranged at an input end of the automatictransmission to connect and disconnect engine power flow to theautomatic transmission and to transfer multiplied torque to theautomatic transmission, the clutch apparatus comprising: a clutch basemounted to a flywheel of an engine and having a supporting boss whichpossesses a cylindrical configuration and is projectedly formed on aninner surface of the clutch base, the supporting boss having firstspline grooves which are defined on a circumferential inner surface ofthe supporting boss; a clutch cover coupled to a circumferential outerportion of the clutch base and having a cylindrical configuration whichis opened at one end in a manner such that a space is defined in theclutch cover, the clutch cover being formed, at a center portion of aclosed surface thereof, with a center hole through which a driven shaftconnected to the automatic transmission is inserted; an output shaftrotatably fitted at one end thereof through the clutch base and at theother end thereof through the center hole of the clutch cover, andhaving a sun gear which is formed on a circumferential outer surface ofthe output shaft and second spline grooves which are defined on acircumferential inner surface of the output shaft; a pair of one-wayrotating bearings fitted around both ends of the output shaft,respectively, in a manner such that the output shaft can be rotated inone direction which is the same as a rotating direction of the flywheeland cannot be rotated in the other direction which is opposite to therotating direction of the flywheel; a plurality of planetary gearsections each possessing a guide shaft and a planetary gear, the guideshaft having one end which is rotatably fitted through the clutch baseand the other end which is rotatably supported by the clutch cover, theplanetary gear being formed on a circumferential outer surface of theguide shaft and being meshed with the sun gear of the output shaft; arotating member having an internal ring gear and third spline grooves,the internal ring gear being formed on a circumferential inner surfaceof the rotating member and being meshed with planetary gears of theplurality of planetary gear sections, the third spline grooves beingdefined on a circumferential outer surface of the rotating member; amultiple disc clutch member having a plurality of inner plates which arefitted around the rotating member and a plurality of outer plates whichare fitted into the supporting boss of the clutch base and each of whichis intervened between two adjoining inner plates, each inner platehaving spline teeth which are formed on a circumferential inner surfacethereof and are splined into the third spline grooves of the rotatingmember, each outer plate having spline teeth which are formed on acircumferential outer surface thereof and are splined into the firstspline grooves of the supporting boss; a pressing plate disposed betweenthe multiple disc clutch member and the clutch cover, the pressing platebeing moved by pressing force which is applied thereto in a manner suchthat the inner plates and the outer plates are tightly engaged one withanother and thereby are locked one to another, the pressing platepossessing an annular plate-shaped configuration; pressing meansarranged between the pressing plate and the clutch cover for applyingpressing force to the pressing plate; and pressing force adjusting meansarranged in a circumferential space which is defined betweencircumferential outer portions of the clutch base and the clutch cover,in a manner such that each pressing force adjusting means is capable ofpivoting movement for changing an axial position of the pressing plateand adjusting a magnitude of pressing force which is applied to themultiple disc clutch member, depending upon a magnitude of centrifugalforce generated by rotating force which is transferred from theflywheel.

According to a second aspect of the present invention, there is provideda clutch apparatus for an automatic transmission, which is arranged atan input end of the automatic transmission to connect and disconnectengine power flow to the automatic transmission and to transfermultiplied torque to the automatic transmission, the clutch apparatuscomprising: a clutch base mounted to a flywheel of an engine and havinga supporting boss and a ring gear boss which are projectedly formed onan inner surface of the clutch base in a manner such that the ring gearboss is placed inward of the supporting boss, the supporting boss havingfirst spline grooves which are defined on a circumferential innersurface of the supporting boss, the ring gear boss having a firstinternal ring gear which is formed on a circumferential inner surface ofthe ring gear boss; a clutch cover coupled to a circumferential outerportion of the clutch base and having a cylindrical configuration whichis opened at one end in a manner such that a space is defined in theclutch cover, the clutch cover being formed, at a center portion of aclosed surface thereof, with a center hole through which a driven shaftconnected to the automatic transmission is inserted; an output shaftrotatably fitted at one end thereof through the clutch base and at theother end thereof through the center hole of the clutch cover, andhaving a sun gear which is formed on a circumferential outer surface ofthe output shaft and second spline grooves which are defined on acircumferential inner surface of the output shaft; a pair of one-wayrotating bearings fitted around both ends of the output shaft,respectively, in a manner such that the output shaft can be rotated inone direction which is the same as a rotating direction of the flywheeland cannot be rotated in the other direction which is opposite to therotating direction of the flywheel; a carrier having a first disc and asecond disc which are coupled with each other by means of a plurality ofconnecting members in a manner such that the first disc and the seconddisc are spaced apart from each other by a predetermined distance, thefirst disc being rotatably brought into contact at one surface thereofwith the inner surface of the clutch base by the medium of a firstthrust bearing, the second disc being rotatably brought into contactwith the clutch cover by the medium of a second thrust bearing; aplurality of double planetary gear sections fitted around the pluralityof connecting members, respectively, in such a way as to be disposed inthe carrier, and each having integrally formed thereon a first planetarygear and a second planetary gear which have different numbers of teethor different modules, the first planetary gear being meshed with thefirst internal ring gear, the second planetary gear being meshed withthe sun gear of the output shaft; a rotating member possessing aring-shaped configuration and having a second internal ring gear andthird spline grooves, the second internal ring gear being formed on acircumferential inner surface of the rotating member and being meshedwith second planetary gears of the plurality of double planetary gearsections, the third spline grooves being defined on a circumferentialouter surface of the rotating member, the second and first internal ringgears having different numbers of teeth or different modules; a multipledisc clutch member having a plurality of inner plates which are fittedaround the rotating member and a plurality of outer plates which arefitted into the supporting boss of the clutch base and each of which isintervened between two adjoining inner plates, each inner plate havingspline teeth which are formed on a circumferential inner surface thereofand are splined into the third spline grooves of the rotating member,each outer plate having spline teeth which are formed on acircumferential outer surface thereof and are splined into the firstspline grooves of the supporting boss; a pressing plate disposed betweenthe multiple disc clutch member and the clutch cover, the pressing platebeing moved by pressing force which is applied thereto in a manner suchthat the inner plates and the outer plates are tightly engaged one withanother and thereby are locked one to another, the pressing platepossessing an annular plate-shaped configuration; pressing meansarranged between the pressing plate and the clutch cover for applyingpressing force to the pressing plate; and pressing force adjusting meansarranged in a circumferential space which is defined betweencircumferential outer portions of the clutch base and the clutch cover,in a manner such that each pressing force adjusting means is capable ofpivoting movement for changing an axial position of the pressing plateand adjusting a magnitude of pressing force which is applied to themultiple disc clutch member, depending upon a magnitude of centrifugalforce generated by rotating force which is transferred from theflywheel.

BRIEF DESCRIPTION OF DRAWINGS

The above objects, and other features and advantages of the presentinvention will become more apparent after a reading of the followingdetailed description when taken in conjunction with the drawings, inwhich:

FIG. 1 is a cross-sectional view schematically illustrating aconstruction of the conventional automatic transmission;

FIG. 2 is an exploded perspective view illustrating a clutch apparatusfor an automatic transmission in accordance with a first embodiment ofthe present invention;

FIG. 3 is a partially broken-away schematic front view illustrating anoperation of the clutch apparatus for an automatic transmission inaccordance with the first embodiment of the present invention;

FIG. 4 is a cross-sectional view taken along the line A—A of FIG. 3,illustrating the clutch apparatus for an automatic transmission inaccordance with the first embodiment of the present invention;

FIG. 5 is an exploded perspective view illustrating a clutch apparatusfor an automatic transmission in accordance with a second embodiment ofthe present invention;

FIG. 6 is a partially broken-away schematic front view illustrating anoperation of the clutch apparatus for an automatic transmission inaccordance with the second embodiment of the present invention;

FIG. 7 is a cross-sectional view taken along the line A—A of FIG. 6,illustrating the clutch apparatus for an automatic transmission inaccordance with the second embodiment of the present invention;

FIG. 8 is a partially broken-away side view illustrating a clutchapparatus for an automatic transmission in accordance with a thirdembodiment of the present invention; and

FIG. 9 is a partially broken-away and partially perspectively enlargedside view illustrating a clutch apparatus for an automatic transmissionin accordance with a fourth embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in greater detail to a preferred embodimentof the invention, an example of which is illustrated in the accompanyingdrawings. Wherever possible, the same reference numerals will be usedthroughout the drawings and the description to refer to the same or likeparts.

FIG. 2 is an exploded perspective view illustrating a clutch apparatusfor an automatic transmission in accordance with a first embodiment ofthe present invention; FIG. 3 is a partially broken-away schematic frontview illustrating an operation of the clutch apparatus for an automatictransmission in accordance with the first embodiment of the presentinvention; and FIG. 4 is a cross-sectional view taken along the line A—Aof FIG. 3, illustrating the clutch apparatus for an automatictransmission in accordance with the first embodiment of the presentinvention.

As shown in FIGS. 2 through 4, a clutch apparatus for an automatictransmission in accordance with a first embodiment of the presentinvention includes a clutch base 120 mounted to a flywheel 40 of anengine and having a supporting boss 122 which is projectedly formed onan inner surface of the clutch base 120, a clutch cover 110 secured tothe clutch base 120, an output shaft 130 rotatably disposed between theclutch base 120 and the clutch cover 110, a pair of one-way rotatingbearings B4 fitted around both ends of the output shaft 130,respectively, in a manner such that the output shaft 130 can be rotatedin one direction which is the same as a rotating direction of theflywheel 40 and cannot be rotated in the other direction which isopposite to the rotating direction of the flywheel 40, a plurality ofplanetary gear sections 140 rotatably disposed between the clutch base120 and the clutch cover 110 in a manner such that they are operativelyconnected to a circumferential outer surface of the output shaft 130, arotating member 150 having a circumferential inner surface which isoperatively connected to the plurality of planetary gear sections 140, amultiple disc clutch member 160 splined to a circumferential outersurface of the rotating member 150 and a circumferential inner surfaceof the supporting boss 122, a pressing plate 170 disposed between themultiple disc clutch member 160 and the clutch cover 110 for applyingpressing force to the multiple disc clutch member 160, pressing means180 arranged between the pressing plate 170 and the clutch cover 110 forapplying pressing force to the pressing plate 170, and pressing forceadjusting means 200 arranged in a circumferential space which is definedbetween circumferential outer portions of the clutch base 120 and theclutch cover 110, in a manner such that each pressing force adjustingmeans 200 is capable of pivoting movement for changing an axial positionof the pressing plate 170 and adjusting a magnitude of pressing forcewhich is applied to the multiple disc clutch member 160, depending upona magnitude of centrifugal force generated by rotating force which istransferred from the flywheel 40. The clutch apparatus according to thisembodiment of the present invention is installed between the engine andthe automatic transmission to connect and disconnect engine power flowto the automatic transmission and to transfer multiplied torque to theautomatic transmission.

The clutch base 120 possesses a disc-shaped configuration. Thesupporting boss 122 is projectedly formed on the inner surface of theclutch base 120 and possesses a cylindrical configuration. First splinegrooves 122 a are defined on the circumferential inner surface of thesupporting boss 122. The clutch base 120 further has a bearingsupporting boss 124 which is projectedly formed on the inner surface ofthe clutch base 120 inward of the supporting boss 122. A ball seatinggroove 124 a is defined on a free end surface of the bearing supportingboss 124. An output shaft inserting hole 126 through which one end ofthe output shaft 130 is inserted, is defined at a center portion of theclutch base 120 inside the bearing supporting boss 124. Shaft insertingholes 128 through which one ends of the plurality of planetary gearsections 140 are inserted, are defined around the output shaft insertinghole 126 inside the bearing supporting boss 124.

The clutch cover 110 is coupled through an outward flange portion 112 toa circumferential outer portion of the clutch base 120 and possesses acylindrical configuration which is opened at one end in a manner suchthat a space is defined in the clutch cover 110. The clutch cover 110 isformed, at a center portion of a closed surface 114 thereof, with acenter hole 116 through which a driven shaft 20 connected to theautomatic transmission is inserted. Planetary gear supporting bosses 118having shaft inserting holes 118 a into which the other ends of theplurality of planetary gear sections 140 are fitted, are projectedlyformed on an inner surface of the clutch cover 110.

The output shaft 130 is rotatably fitted at one end thereof through theoutput shaft inserting hole 126 of the clutch base 120 and at the otherend thereof through the center hole 116 of the clutch cover 110. Theoutput shaft 130 has a sun gear 132 which is formed on thecircumferential outer surface of the output shaft 130 and second splinegrooves 134 which are defined on a circumferential inner surface of theoutput shaft 130. The driven shaft 20 is splined into the second splinegrooves 134.

Each of the plurality of planetary gear sections 140 possesses a guideshaft 144 and a planetary gear 142. The guide shaft 144 has one endwhich is rotatably fitted through the shaft inserting hole 128 of theclutch base 120 and the other end which is rotatably fitted through theshaft inserting hole 118 a of the clutch cover 110. The planetary gear142 is formed on a circumferential outer surface of the guide shaft 144and is meshed with the sun gear 132 of the output shaft 130. While fourplanetary gear sections 140 are provided in this first embodiment of thepresent invention, a person skilled in the art will readily appreciatethat two or more planetary gear sections can be properly used withoutdeparting from the scope of the present invention.

A plurality of bearings B3 are fitted around both ends of the guideshafts 144 of the plurality of planetary gear sections 140.

The rotating member 150 has an internal ring gear 152 and third splinegrooves 154. The internal ring gear 152 is formed on the circumferentialinner surface of the rotating member 150 and is meshed with theplanetary gears 142 of the plurality of planetary gear sections 140. Thethird spline grooves 154 are defined on the circumferential outersurface of the rotating member 150.

The multiple disc clutch member 160 has a plurality of inner plates 162which are fitted around the rotating member 150 and a plurality of outerplates 364 which are fitted into the supporting boss 122 of the clutchbase 120 and each of which is intervened between two adjoining innerplates 162. Each inner plate 162 has spline teeth 162 a which are formedon a circumferential inner surface thereof and are splined into thethird spline grooves 154 of the rotating member 150. Each outer plate164 has spline teeth 164 a which are formed on a circumferential outersurface thereof and are splined into the first spline grooves 122 a ofthe supporting boss 122 of the clutch base 120.

The pressing plate 170 is correspondingly disposed between the multipledisc clutch member 160 and the clutch cover 110. The pressing plate 170is moved by pressing force which is applied thereto in a manner suchthat the inner plates 162 and the outer plates 164 are tightly engagedone with another and thereby are locked one to another. The pressingplate 170 possesses an annular plate-shaped configuration. A pressingsurface 172 is projectedly defined on an inner surface of the pressingplate 170. Adjacent to a circumferential outer edge of the pressingplate 170, there are defined a plurality of support bar inserting holes174 in a manner such that they are spaced apart one from another by apredetermined angle, in a circumferential direction.

The pressing means 180 comprises a plurality of first magnets 182 whichare disposed on an outer surface of the pressing plate 170 to define acircular arrangement, and a plurality of second magnets 184 which aredisposed on the inner surface of the clutch cover 110 in a manner suchthat the second magnets 184 are opposite to the first magnets 182,respectively. The first and second magnets 182 and 184 have the samepolarity to create repulsive force therebetween.

A plurality of magnet receiving grooves 170 a and 110 a are defined onthe outer surface of the pressing plate 170 and the inner surface of theclutch cover 110 so that the first magnets 182 and the second magnets184 of the pressing means 180 are received in the magnet receivinggrooves 170 a and 110 a, respectively.

Each pressing force adjusting means 200 includes a support bar 210, abalancing weight 220, a compression spring 230, a bearing-supportingring 240, a pair of guide bearings 250, and an elastic member 260. Thesupport bar 210 is fastened at both ends thereof to the clutch base 120and the clutch cover 110, respectively, in a manner such that thesupport bar 210 is arranged in the circumferential space which isdefined between circumferential outer portions of the clutch base 120and the clutch cover 110 and the pressing plate 170 is fitted around thesupport bar 210 to be capable of being moved in an axial direction. Thesupport bar 210 has an externally threaded portion which is formed on acircumferential outer surface and at a middle portion of the support bar210. The balancing weight 220 has one end which is fitted around thesupport bar 210, to be pivotally rotated about the one end. Thecompression spring 230 is fitted around the support bar 210 for applyingelastic force to the balancing weight 220. The bearing-supporting ring240 is fitted around the support bar 210 in a manner such that thebearing-supporting ring 210 is brought into contact with an end of thecompression spring 230. The pair of guide bearings 250 are fitted aroundthe support bar 210 and located at both sides, respectively, of the oneend of the balancing weight 220, to smooth pivotal rotation of thebalancing weight 220. The elastic member 260 has one end which issecured to the other end of the balancing weight 220 and the other endwhich is secured to the inner surface of the clutch cover 110, so thatthe elastic member 260 can return the balancing weight 220 which ispivotally rotated by the centrifugal force, to its original position.

The balancing weight 220 possesses substantially a hexahedron-shapedconfiguration. The balancing weight 220 is formed, at both ends thereof,with two semi-circular coupling portions 222 each of which is definedwith a bore 222 a. A circumferential ball seating groove is definedaround the bore 222 a on a surface of the semi-circular coupling portion222 which surface faces the support bar inserting hole 174, to allow theballs of the guide bearing 250 to be received therein.

The elastic member 260 comprises a torsion spring, and bushings 262 arefitted around both ends of the elastic member 260, respectively. One endof the elastic member 260 is inserted through the bore 222 a which isdefined in one semi-circular coupling portion 222 of the balancingweight 220, and the other end of the elastic member 260 is secured tothe inner surface of the clutch cover 110.

On the other hand, a first thrust bearing R1 is intervened between thebearing supporting boss 124 of the clutch base 120 and one end of therotating member 150, a second thrust bearing R2 is intervened betweenthe other end of the rotating member 150 and the inner surface of theclutch cover 110, and both end surfaces of the rotating member 150 andthe inner surface of the clutch cover 110, on which the first and secondthrust bearings R1 and R2 are seated, respectively, are formed with ballseating grooves to allow balls of the bearings R1 and R2 to be rollablyreceived therein.

In FIGS. 2 through 4, the drawing reference numeral B1 represents abearing on which one end of the driven shaft 20 is rotatably supported.

Hereinafter, operations of the clutch apparatus for an automatictransmission according to the first embodiment of the present inventionwill be described in detail.

As can be readily seen from FIGS. 3 and 4, due to the repulsive forcewhich is developed between the first magnets 182 and the second magnets184, the pressing plate 170 exerts pressing force on the multiple discclutch member 160, and, by dint of this, the inner plates 162 and theouter plates 164 are tightly engaged one with another. That is to say,if rotating force is transferred to the flywheel 40 as the engine isdriven, since the outer plates 164 are splined into the first splinegrooves 122 a which are defined on the circumferential inner surface ofthe supporting boss 122 of the clutch base 120 and the inner plates 162are splined into the third spline grooves 154 which are defined on thecircumferential outer surface of the rotating member 150, the innerplates 162 and the outer plates 164 are tightly engaged one withanother, and, in this state, the rotating member 150 cannot be rotated.

Because rotation of the rotating member 150 is impossible, the rotatingforce of the flywheel 40, which is transferred to the internal ring gear152 of the rotating member 150 through the plurality of planetary gearsections 140, flows to the sun gear 132 of the output shaft 130, whichis meshed with the planetary gears 142 of the planetary gear sections140, and then, is transferred to the driven shaft 20 which is splinedinto the second spline grooves 134 of the output shaft 130.

Accordingly, the rotating force of the flywheel 40, which is generatedby driving of the engine, flows to the automatic transmission throughthe driven shaft 20.

In the meanwhile, when the inner plates 162 and the outer plates 164 ofthe multiple disc clutch member 160 are tightly engaged one with anotherby external force which is generated by the pressing means 180 and therotating force of the flywheel 40 is transferred to the driven shaft 20,the pressing force adjusting means 200 serve to maximize a powertransfer efficiency, depending upon an engine RPM. Namely, in the casethat a driver forcibly depresses an accelerator pedal, as an engine RPMincreases, the flywheel 40 is rotated at a high rotational velocity.With this, as an RPM of the clutch base 120 and the clutch cover 110which are rotated in an interlocked manner with the flywheel 40,increases, centrifugal force is generated by the balancing weights 220which are arranged in the circumferential space which in turn is definedbetween the circumferential outer portions of the clutch base 120 andthe clutch cover 110, whereby the balancing weights 220 are pivotallyrotated in a direction which is shown by a solid arrow in FIG. 3.According to this, the compression springs 230 are compressed and thebalancing weights 220 are moved along the support bars 210 in adirection which is shown by a solid arrow in FIG. 4.

Therefore, because the pressing plate 170 is freed from a state whereinit is maintained at a fixed location by elastic force of the compressionsprings 230, the pressing plate 170 is forcibly pushed by the repulsiveforce which is generated by the first and second magnets 182 and 184,toward the multiple disc clutch member 160. By this, biasing force fortightly engaging the inner plates 162 and the outer plates 164 of themultiple disc clutch member 160 one with another is increased, wherebythe rotating force of the flywheel 40 is transferred to the driven shaft20 in a precise manner.

In other words, in the case that an engine RPM increases, power transferof high precision and high efficiency can be accomplished.

On the other hand, if the driver decreases depressing force which isapplied to the accelerator pedal, as an engine RPM decreases, theflywheel 40 is rotated at a low rotational velocity. Also, since an RPMof the clutch base 120 and the clutch cover 110 which are rotated in theinterlocked manner with the flywheel 40, decreases, centrifugal forcewhich is generated by the balancing weights 220 arranged in thecircumferential space, is also reduced. According to this, the balancingweights 220 are returned to their original positions by the elasticforce of the elastic members 260 in a direction which is shown by adotted arrow in FIG. 3. At this time, as the balancing weights 220 arereturned to their original positions after being moved along the supportbars 210, respectively, in a direction which is shown by a dotted arrowin FIG. 4, the pressing plate 170 is also returned to its originalposition, whereby pressing force which is applied to the multiple discclutch member 160, is reduced to be set to an initial value.

Accordingly, by the presence of the pressing force adjusting means 200,power transfer is implemented in an adequate manner, depending upon anengine RPM, whereby high efficiency power transfer is possible.

Meanwhile, because the pair of one-way rotating bearings B4 support theoutput shaft 130 in a manner such that the output shaft 130 can berotated in the one direction which is the same as the rotating directionof the flywheel 40 and cannot be rotated in the other direction which isopposite to the rotating direction of the flywheel 40, if rotating forceis transferred to the pair of one-way rotating bearings B4 in a reversedirection from the driven shaft 20, the rotating force can flow to theflywheel 40 through the output shaft 130, the planetary gears 142 andthe clutch base 120. As a consequence, an engine brake operation can befulfilled, by which it is possible to ensure safe driving of a motorvehicle and the engine can be started by pushing the motor vehicle underan emergency situation such as discharge of a battery.

FIG. 5 is an exploded perspective view illustrating a clutch apparatusfor an automatic transmission in accordance with a second embodiment ofthe present invention; FIG. 6 is a partially broken-away schematic frontview illustrating an operation of the clutch apparatus for an automatictransmission in accordance with the second embodiment of the presentinvention; and FIG. 7 is a cross-sectional view taken along the line A—Aof FIG. 6, illustrating the clutch apparatus for an automatictransmission in accordance with the second embodiment of the presentinvention. In this second embodiment of the present invention, the samedrawing reference numerals will be used to designate the same parts asthose in the first embodiment of the present invention.

As shown in FIGS. 5 through 7, a clutch apparatus for an automatictransmission in accordance with a second embodiment of the presentinvention includes a clutch base 320 mounted to a flywheel 40 of anengine and having a supporting boss 322 and a ring gear boss 324 whichare projectedly formed on an inner surface of the clutch base 320 in amanner such that the ring gear boss 324 is placed inward of thesupporting boss 322, a clutch cover 310 secured to the clutch base 320,an output shaft 330 rotatably disposed between the clutch base 320 andthe clutch cover 310, a pair of one-way rotating bearings B4 fittedaround both ends of the output shaft 330, respectively, in a manner suchthat the output shaft 330 can be rotated in one direction which is thesame as a rotating direction of the flywheel 40 and cannot be rotated inthe other direction which is opposite to the rotating direction of theflywheel 40, a carrier 340 disposed between the clutch base 320 and theclutch cover 310, a plurality of double planetary gear sections 350arranged in the carrier 340 and each having integrally formed thereon afirst planetary gear 352 which is operatively connected to the ring gearboss 324 and a second planetary gear 354 which is operatively connectedto the output shaft 330, a rotating member 360 having a circumferentialinner surface which is operatively connected to second planetary gears354 of the plurality of double planetary gear sections 350, a multipledisc clutch member 160 splined to a circumferential outer surface of therotating member 360 and a circumferential inner surface of thesupporting boss 322, a pressing plate 170 for applying pressing force tothe multiple disc clutch member 160, pressing means 180 for applyingpressing force to the pressing plate 170, and pressing force adjustingmeans 200 arranged in a circumferential space which is defined betweencircumferential outer portions of the clutch base 320 and the clutchcover 310, in a manner such that each pressing force adjusting means 200is capable of pivoting movement for changing an axial position of thepressing plate 170 and adjusting a magnitude of pressing force which isapplied to the multiple disc clutch member 160, depending upon amagnitude of centrifugal force generated by rotating force which istransferred from the flywheel 40. The clutch apparatus according to thisembodiment of the present invention is installed between the engine andthe automatic transmission to connect and disconnect engine power flowto the automatic transmission and to transfer multiplied torque to theautomatic transmission.

The clutch base 320 possesses a disc-shaped configuration. As describedabove, the supporting boss 322 and the ring gear boss 324 are formed onthe inner surface of the clutch base 320. The supporting boss 322 andthe ring gear boss 324 possess a cylindrical configuration and aring-shaped configuration, respectively. An output shaft inserting hole326 through which one end of the output shaft 330 is inserted, isdefined at a center portion of the clutch base 320. First spline grooves322 a are defined on the circumferential inner surface of the supportingboss 322. A first internal ring gear 324 a is formed on acircumferential inner surface of the ring gear boss 324.

The clutch cover 310 is coupled to a circumferential outer portion ofthe clutch base 320 and possesses a cylindrical configuration which isopened at one end in a manner such that a space is defined in the clutchcover 310. An outward flange portion 312 is formed at the one end of theclutch cover 310 in a manner such that the outward flange portion 312extends in radial and circumferential directions to allow the clutchcover 310 to be coupled to the clutch base 320 thereat. The clutch cover310 is formed, at a center portion of a closed surface 314 thereof, witha center hole 316 through which a driven shaft 20 connected to theautomatic transmission is inserted.

The output shaft 330 is rotatably fitted at one end thereof through theoutput shaft inserting hole 326 of the clutch base 320 and at the otherend thereof through the center hole 316 of the clutch cover 310. Theoutput shaft 330 has a sun gear 332 which is formed on a circumferentialouter surface of the output shaft 330 and second spline grooves 334which are defined on a circumferential inner surface of the output shaft330.

The carrier 340 has a first disc 342 and a second disc 344 which arecoupled with each other by means of a plurality of connecting members346 in a manner such that the first disc 342 and the second disc 344 arespaced apart from each other by a predetermined distance. The first disc342 is rotatably brought into contact at one surface thereof with theinner surface of the clutch base 320 by the medium of a first thrustbearing R1, and the second disc 344 is rotatably brought into contactwith the clutch cover 310 by the medium of a fourth thrust bearing R4.

The first planetary gear 352 of the double planetary gear section 350 ismeshed with the first internal ring gear 324 a of the ring gear boss324, and the second planetary gear 354 of the double planetary gearsection 350 is meshed with the sun gear 332 of the output shaft 330.

The rotating member 360 possesses a ring-shaped configuration and has asecond internal ring gear 362 and third spline grooves 364. The secondinternal ring gear 362 is formed on the circumferential inner surface ofthe rotating member 360 and is meshed with the second planetary gears354 of the plurality of double planetary gear sections 350. The thirdspline grooves 364 are defined on the circumferential outer surface ofthe rotating member 360. At this time, the second internal ring gear 362is formed to have the number of teeth or a module which is differentfrom that of the first internal ring gear 324 a.

The multiple disc clutch member 160 has a plurality of inner plates 162which are fitted around the rotating member 360 and a plurality of outerplates 164 which are fitted into the supporting boss 322 of the clutchbase 320 and each of which is intervened between two adjoining innerplates 162. Each inner plate 162 has spline teeth 162 a which are formedon a circumferential inner surface thereof and are splined into thethird spline grooves 364 of the rotating member 360. Each outer plate164 has spline teeth 164 a which are formed on a circumferential outersurface thereof and are splined into the first spline grooves 322 a ofthe supporting boss 322.

The pressing plate 170, the pressing means 180 and the pressing forceadjusting means 200 of this embodiment are structured in the same way asthose of the first embodiment.

On the other hand, a second thrust bearing R2 is intervened between thering gear boss 324 of the clutch base 320 and one end of the rotatingmember 360, and a third thrust bearing R3 is intervened between theother end of the rotating member 360 and the second disc 344 of thecarrier 340, to enable the rotating member 360 to be smoothly rotated.

Both end surfaces of the rotating member 360 and the inner surfaces ofthe clutch base 320 and the clutch cover 310, on which the first andfourth thrust bearings R1 and R4 are seated, respectively, are formedwith ball seating grooves as denoted by the drawing reference numeral324 b, to allow balls of the bearings R1 and R4 to be rollably receivedtherein.

In FIGS. 5 through 7, the drawing reference numeral B1 represents abearing on which one end of the driven shaft 20 is rotatably supported.

Hereinafter, operations of the clutch apparatus for an automatictransmission according to the second embodiment of the present inventionwill be described in detail.

As shown in FIGS. 5 through 7, in the clutch apparatus for an automatictransmission, according to the second embodiment of the presentinvention, due to the repulsive force which is developed between thefirst magnets 182 and the second magnets 184 of the pressing means 180,the pressing plate 170 exerts pressing force on the multiple disc clutchmember 160, and, by dint of this, the inner plates 162 and the outerplates 164 are tightly engaged one with another.

At this time, due to the fact that the outer plates 164 are splined tothe supporting boss 322 of the clutch base 320 and the inner plates 162are splined to the rotating member 360, in a state wherein the innerplates 162 and the outer plates 164 are tightly engaged one withanother, the rotating member 360 cannot be rotated.

Rotating force of the flywheel 40 is transferred to the first planetarygears 352 of the plurality of double planetary gear sections 350, whichare meshed with the first internal ring gear 324 a of the ring gear boss324 of the clutch base 320, and then, to the second planetary gears 354which are integrally formed with the first planetary gears 352. However,as described above, because the rotating member 360 is captured by themultiple disc clutch member 160 and thereby cannot be rotated, therotating force of the flywheel 40 is transferred to the sun gear 332 ofthe output shaft 330, which is meshed with the second planetary gears354, to rotate the output shaft 330, and then, is transferred to thedriven shaft 20 which is inserted into the output shaft 330.

Accordingly, the rotating force of the flywheel 40, which is generatedby driving of the engine, flows to the automatic transmission throughthe driven shaft 20.

In the meanwhile, as aforementioned above when describing the operationsof the clutch apparatus according to the first embodiment, when theinner plates 162 and the outer plates 164 of the multiple disc clutchmember 160 are tightly engaged one with another by the pressing means180 and the rotating force of the flywheel 40 is transferred to thedriven shaft 20, the pressing force adjusting means 200 serve tomaximize a power transfer efficiency, depending upon an engine RPM.Therefore, power transfer is effected in an optimal manner relying uponan engine RPM.

In the procedure of transferring engine power, wherein the rotatingforce of the flywheel 40 is transferred in order of the first planetarygears 352, the second planetary gears 354 and the sun gear 332, apredetermined reduction gear ratio is obtained by the first and secondplanetary gears 352 and 354 which have different numbers of teeth ordifferent modules. Hence, a friction rate of the multiple disc clutchmember 160 is lessened and thereby a lifetime of components of theclutch apparatus is lengthened.

Meanwhile, because the pair of one-way rotating bearings B4 support theoutput shaft 330 in a manner such that the output shaft 330 can berotated in the one direction which is the same as the rotating directionof the flywheel 40 and cannot be rotated in the other direction which isopposite to the rotating direction of the flywheel 40, if rotating forceis transferred to the pair of one-way rotating bearings B4 in a reversedirection from the driven shaft 20, the rotating force can flow to theflywheel 40 through the output shaft 330, the first and second planetarygears 352 and 354 and the clutch base 320. As a consequence, an enginebrake operation can be fulfilled, by which it is possible to ensure safedriving of a motor vehicle and the engine can be started by pushing themotor vehicle under an emergency situation such as discharge of abattery.

FIG. 8 is a partially broken-away side view illustrating a clutchapparatus for an automatic transmission in accordance with a thirdembodiment of the present invention. In this third embodiment of thepresent invention, the same drawing reference numerals will be used todesignate the same parts as those in the first and second embodiments ofthe present invention.

A clutch apparatus for an automatic transmission in accordance with athird embodiment of the present invention can be constructed in the sameway as that of the first embodiment or the second embodiment, exceptthat the pressing means 180 for applying pressing force to the pressingplate 170 comprises a plurality of coil springs 186 which have one endswhich are fastened to the outer surface of the pressing plate 170 andthe other ends which are fastened to the inner surface of the clutchcover 110 or 310.

The outer surface of the pressing plate 170 to which the one ends of thecoil springs 186 are fastened and the inner surface of the clutch cover110 or 310 to which the other ends of the coil springs 186 are fastened,are formed with a plurality of spring inserting grooves.

On the other hand, the plurality of coil springs 186 perform the samefunction of pressing the pressing plate 170 as the first and secondmagnets 182 and 184 of the first and second embodiments.

FIG. 9 is a partially broken-away and partially perspectively enlargedside view illustrating a clutch apparatus for an automatic transmissionin accordance with a fourth embodiment of the present invention. In thisfourth embodiment of the present invention, the same drawing referencenumerals will be used to designate the same parts as those in the firstand second embodiments of the present invention.

A clutch apparatus for an automatic transmission in accordance with afourth embodiment of the present invention can be constructed in thesame way as that of the first embodiment or the second embodiment,except that the pressing means 180 for pressing the multiple disc clutchmember 160 comprises a hydraulic device 400 which is disposed in theclutch cover 110 or 310 and controlled by a control unit (not shown)controlling engine output, such as an engine electronic control moduleor the like, and an annular leaf spring 400 a is installed on thesupporting boss 122 or 322 of the clutch base 120 or 320 to exertelastic pressing force on the hydraulic device 400 thereby to removeexternal force which is applied to the multiple disc clutch member 160by the hydraulic device 400. In the clutch apparatus according to thisembodiment of the present invention, a magnitude of pressing force whichis applied to the multiple disc clutch member 160 is adjusted by thehydraulic device 400, whereby a separate pressing force adjusting meansas given in the first and second embodiments are not needed.

The hydraulic device 400 comprises a piston guide part 410, an oil inletpart 420, an oil supplying line 430, a piston 440, and a line connectingmember 450. The piston guide part 410 is projectedly formed on an innersurface of the clutch cover 110 or 310, which surface faces the multipledisc clutch member 160, to define an annular configuration. The pistonguide part 410 has a pair of piston guide grooves 412. The oil inletpart 420 is projectedly formed on an outer surface of the clutch cover110 or 310 to define a ring-shaped configuration and has an oil groove422 which is defined on a distal end surface of the oil inlet part 420.The oil supplying line 430 is formed in a manner such that the oilsupplying line 430 extends between the oil groove 422 of the oil inletpart 420 and a distal end of the piston rod guide part 410. The piston440 is brought into contact with the multiple disc clutch member 160 bya pressure of oil which is supplied through the oil supplying line 430.The piston 440 has a body which takes a U-shaped cross-section and aspring supporting projection 442 against which an end of the annularleaf spring 400 a is supported. The line connecting member 450 iscoupled to the oil inlet part 420 and fixedly maintained in a mannersuch that the clutch cover 110 or 310 can be freely rotated with respectto the line connecting member 450. The line connecting member 450 has aconnector 452 which is formed with an oil hole 454 which in turn iscommunicated with the oil groove 422 of the oil inlet part 420.

A circumferential inner surface of the piston 440 and opposite surfacesof the line connecting member 450 and the oil inlet part 420 which arebrought into sliding contact with each other, are defined withcircumferential grooves into which leakage preventing members such asO-rings 456 are fitted for preventing oil from leaking.

While not shown in the drawings, the hydraulic device 400 is providedwith additional parts including a pipeline which is connected with theconnector 452, a control valve which controls a flow direction and apressure of oil supplied through the pipeline, an oil pump whichsupplies compressed oil, and so on. The additional parts can be modifiedinto a variety of forms within the scope of the present invention.

A circumferential outer end of the cylindrical supporting boss 122 or322 is formed with a spring supporting sleeve 122 b or 322 b againstwhich the other end of the annular leaf spring 400 a is fastened.

Hereinafter, operations of the car clutch according to the fourthembodiment of the present invention will be described in detail.

If an engine RPM is supplied as an operating signal to the hydraulicdevice 400 from an engine electronic control system, oil is suppliedthrough the oil supplying line 430 to bias the piston 440 in the onedirection toward the clutch base 120 or 320, and thereby external forceis applied to the multiple disc clutch member 160, whereby the innerplates 162 and the outer plates 164 are tightly engaged one withanother. By this, through the same operations as described inassociation with the first embodiment or the second embodiment of thepresent invention, the rotating force of the flywheel 40 is preciselytransferred to the driven shaft 20. At this time, in the case that anengine RPM increases, the hydraulic device 400 presses the multiple discclutch member 160 with elevated pressing force, thereby to accomplish ahigh power transfer efficiency.

On the other hand, if an engine RPM decreases, the annular leaf spring400 a forces the spring supporting projection 442 to move in the otherdirection toward the clutch cover 110 or 310 by its own elastic force.Due to this, as the oil which is compressively supplied into the piston440, is drained, a magnitude of pressing force which is applied to themultiple disc clutch member 160 is reduced. Therefore, power transfer tothe automatic transmission can be properly effected.

INDUSTRIAL APPLICABILITY

As a result, the clutch apparatus for an automatic transmissionaccording to the present invention provides advantages in that, sincethe clutch apparatus transfers engine power to the automatictransmission using a mechanical arrangement including planetary gearsand the like rather than using fluid, power loss due to fluid frictionis not caused, whereby a power transfer efficiency is increased, passingand acceleration capability of a motor vehicle is improved, and amaximum speed is raised.

Moreover, due to the fact that the clutch apparatus transfers enginepower to the automatic transmission using the mechanical arrangement, acomplicated hydraulic mechanism and a cooling apparatus are not needed,by which a simple construction is achieved. Consequently, manufacturingcost is reduced and productivity is increased.

Furthermore, because force of a driven side of the motor vehicle can betransferred to a driving side of the motor vehicle along a reversedirection, an engine brake operation can be fulfilled, by which safedriving of the motor vehicle is ensured. In addition, due to the factthat an engine of the motor vehicle can be started by pushing the motorvehicle, it is possible to cope with an emergency situation such asdischarge of a battery.

What is claimed is:
 1. A clutch apparatus for an automatic transmission,which is arranged at an input end of the automatic transmission toconnect and disconnect engine power flow to the automatic transmissionand to transfer multiplied torque to the automatic transmission, theclutch apparatus comprising: a clutch base mounted to a flywheel of anengine and having a supporting boss which possesses a cylindricalconfiguration and is projectedly formed on an inner surface of theclutch base, the supporting boss having first spline grooves which aredefined on a circumferential inner surface of the supporting boss; aclutch cover coupled to a circumferential outer portion of the clutchbase and possessing a cylindrical configuration which is opened at oneend in a manner such that a space is defined in the clutch cover, theclutch cover being formed, at a center portion of a closed surfacethereof, with a center hole through which a driven shaft connected tothe automatic transmission is inserted; an output shaft rotatably fittedat one end thereof through the clutch base and at the other end thereofthrough the center hole of the clutch cover, and having a sun gear whichis formed on a circumferential outer surface of the output shaft andsecond spline grooves which are defined on a circumferential innersurface of the output shaft; a pair of one-way rotating bearings fittedaround both ends of the output shaft, respectively, in a manner suchthat the output shaft can be rotated in one direction which is the sameas a rotating direction of the flywheel and cannot be rotated in theother direction which is opposite to the rotating direction of theflywheel; a plurality of planetary gear sections each possessing a guideshaft and a planetary gear, the guide shaft having one end which isrotatably fitted through the clutch base and the other end which isrotatably supported by the clutch cover, the planetary gear being formedon a circumferential outer surface of the guide shaft and being meshedwith the sun gear of the output shaft; a rotating member having aninternal ring gear and third spline grooves, the internal ring gearbeing formed on a circumferential inner surface of the rotating memberand being meshed with planetary gears of the plurality of planetary gearsections, the third spline grooves being defined on a circumferentialouter surface of the rotating member; a multiple disc clutch memberhaving a plurality of inner plates which are fitted around the rotatingmember and a plurality of outer plates which are fitted into thesupporting boss of the clutch base and each of which is intervenedbetween two adjoining inner plates, each inner plate having spline teethwhich are formed on a circumferential inner surface thereof and aresplined into the third spline grooves of the rotating member, each outerplate having spline teeth which are formed on a circumferential outersurface thereof and are splined into the first spline grooves of thesupporting boss; a pressing plate disposed between the multiple discclutch member and the clutch cover, the pressing plate being moved bypressing force which is applied thereto in a manner such that the innerplates and the outer plates are tightly engaged one with another andthereby are locked one to another, the pressing plate possessing anannular plate-shaped configuration; pressing means arranged between thepressing plate and the clutch cover for applying pressing force to thepressing plate; and pressing force adjusting means arranged in acircumferential space which is defined between circumferential outerportions of the clutch base and the clutch cover, in a manner such thateach pressing force adjusting means is capable of pivoting movement forchanging an axial position of the pressing plate and adjusting amagnitude of pressing force which is applied to the multiple disc clutchmember, depending upon a magnitude of centrifugal force generated byrotating force which is transferred from the flywheel.
 2. The clutchapparatus as claimed in claim 1, wherein the pressing means comprises aplurality of first magnets which are disposed on an outer surface of thepressing plate to define a circular arrangement, and a plurality ofsecond magnets which are disposed on an inner surface of the clutchcover in a manner such that the second magnets are opposite to the firstmagnets, respectively, the first and second magnets having the samepolarity to create repulsive force therebetween.
 3. The clutch apparatusas claimed in claim 1, wherein the pressing means comprises a pluralityof coil springs having one ends which are fastened to an outer surfaceof the pressing plate and the other ends which are fastened to an innersurface of the clutch cover.
 4. The clutch apparatus as claimed in claim1, wherein the pressing means comprises a hydraulic device which isdisposed in the clutch cover and controlled by a control unitcontrolling engine output, and an annular leaf spring is installed onthe supporting boss of the clutch base to exert elastic pressing forceon the hydraulic device thereby to remove external force which isapplied to the multiple disc clutch member by the hydraulic device. 5.The clutch apparatus as claimed in claim 1, wherein each pressing forceadjusting means comprises: a support bar fastened at both ends thereofto the clutch base and the clutch cover, respectively, in a manner suchthat the support bar is arranged in the circumferential space which isdefined between circumferential outer portions of the clutch base andthe clutch cover and the pressing plate is fitted around the support barto be capable of being moved in an axial direction, the support barhaving an externally threaded portion which is formed on acircumferential outer surface and at a middle portion of the supportbar; a balancing weight having one end which is fitted around thesupport bar, to be pivotally rotated about the one end; a compressionspring fitted around the support bar for applying elastic force to thebalancing weight; a bearing-supporting ring fitted around the supportbar in a manner such that the bearing-supporting ring is brought intocontact with an end of the compression spring; a pair of guide bearingsfitted around the support bar and located at both sides, respectively,of the one end of the balancing weight, to smooth pivotal rotation ofthe balancing weight; and an elastic member having one end which issecured to the other end of the balancing weight and the other end whichis secured to the inner surface of the clutch cover, so that the elasticmember can return the balancing weight which is pivotally rotated by thecentrifugal force, to its original position.
 6. The clutch apparatus asclaimed in claim 4, wherein the hydraulic device comprises: a pistonguide part projectedly formed on an inner surface of the clutch cover,which surface faces the multiple disc clutch member, to define anannular configuration, the piston guide part having a pair of pistonguide grooves; an oil inlet part projectedly formed on an outer surfaceof the clutch cover to define a ring-shaped configuration and having anoil groove which is defined on a distal end surface of the oil inletpart; an oil supplying line formed in a manner such that the oilsupplying line extends between the oil groove of the oil inlet part anda distal end of the piston rod guide part; a piston brought into contactwith the multiple disc clutch member by a pressure of oil which issupplied through the oil supplying line, the piston having a body whichtakes a U-shaped cross-section and a spring supporting projectionagainst which an end of the annular leaf spring is supported; and a lineconnecting member coupled to the oil inlet part and fixedly maintainedin a manner such that the clutch cover can be freely rotated withrespect to the line connecting member, the line connecting member havinga connector which is formed with an oil hole which in turn iscommunicated with the oil groove of the oil inlet part.
 7. A clutchapparatus for an automatic transmission, which is arranged at an inputend of the automatic transmission to connect and disconnect engine powerflow to the automatic transmission and to transfer multiplied torque tothe automatic transmission, the clutch apparatus comprising: a clutchbase mounted to a flywheel of an engine and having a supporting boss anda ring gear boss which are projectedly formed on an inner surface of theclutch base in a manner such that the ring gear boss is placed inward ofthe supporting boss, the supporting boss having first spline grooveswhich are defined on a circumferential inner surface of the supportingboss, the ring gear boss having a first internal ring gear which isformed on a circumferential inner surface of the ring gear boss; aclutch cover coupled to a circumferential outer portion of the clutchbase and having a cylindrical configuration which is opened at one endin a manner such that a space is defined in the clutch cover, the clutchcover being formed, at a center portion of a closed surface thereof,with a center hole through which a driven shaft connected to theautomatic transmission is inserted; an output shaft rotatably fitted atone end thereof through the clutch base and at the other end thereofthrough the center hole of the clutch cover, and having a sun gear whichis formed on a circumferential outer surface of the output shaft andsecond spline grooves which are defined on a circumferential innersurface of the output shaft; a pair of one-way rotating bearings fittedaround both ends of the output shaft, respectively, in a manner suchthat the output shaft can be rotated in one direction which is the sameas a rotating direction of the flywheel and cannot be rotated in theother direction which is opposite to the rotating direction of theflywheel; a carrier having a first disc and a second disc which arecoupled with each other by means of a plurality of connecting members ina manner such that the first disc and the second disc are spaced apartfrom each other by a predetermined distance, the first disc beingrotatably brought into contact at one surface thereof with the innersurface of the clutch base by the medium of a first thrust bearing, thesecond disc being rotatably brought into contact with the clutch coverby the medium of a second thrust bearing; a plurality of doubleplanetary gear sections fitted around the plurality of connectingmembers, respectively, in such a way as to be disposed in the carrier,and each having integrally formed thereon a first planetary gear and asecond planetary gear which have different numbers of teeth or differentmodules, the first planetary gear being meshed with the first internalring gear, the second planetary gear being meshed with the sun gear ofthe output shaft; a rotating member possessing a ring-shapedconfiguration and having a second internal ring gear and third splinegrooves, the second internal ring gear being formed on a circumferentialinner surface of the rotating member and being meshed with secondplanetary gears of the plurality of double planetary gear sections, thethird spline grooves being defined on a circumferential outer surface ofthe rotating member, the second and first internal ring gears havingdifferent numbers of teeth or different modules; a multiple disc clutchmember having a plurality of inner plates which are fitted around therotating member and a plurality of outer plates which are fitted intothe supporting boss of the clutch base and each of which is intervenedbetween two adjoining inner plates, each inner plate having spline teethwhich are formed on a circumferential inner surface thereof and aresplined into the third spline grooves of the rotating member, each outerplate having spline teeth which are formed on a circumferential outersurface thereof and are splined into the first spline grooves of thesupporting boss; a pressing plate disposed between the multiple discclutch member and the clutch cover, the pressing plate being moved bypressing force which is applied thereto in a manner such that the innerplates and the outer plates are tightly engaged one with another andthereby are locked one to another, the pressing plate possessing anannular plate-shaped configuration; pressing means arranged between thepressing plate and the clutch cover for applying pressing force to thepressing plate; and pressing force adjusting means arranged in acircumferential space which is defined between circumferential outerportions of the clutch base and the clutch cover, in a manner such thateach pressing force adjusting means is capable of pivoting movement forchanging an axial position of the pressing plate and adjusting amagnitude of pressing force which is applied to the multiple disc clutchmember, depending upon a magnitude of centrifugal force generated byrotating force which is transferred from the flywheel.